[Seroprevalence of hepatitis E virus (Hepeviridae: Orthohepevirus: Orthohepevirus A) among pregnant women in the highly endemic region of Kyrgyzstan].

INTRODUCTION: Hepatitis E (HE) is an important public health problem worldwide and is especially significant for pregnant women, among whom the associated mortality rate reaches 25%. The distribution of HE serological markers in this cohort in the endemic regions of Central Asia is poorly understood. The aim of the study was to assess the seroprevalence of HEV among pregnant women in the region of Kyrgyzstan where an increased incidence of HE is reported. MATERIAL AND METHODS: Blood serum of pregnant women, obtained from medical institutions in Bishkek, city of Osh and Osh region in the period from September 2016 to October 2019, and the control group of clinically healthy women were tested using the test systems "DS-IFA-ANTI-HEV-G" and "DS-IFA-ANTI-HEV-M" (NPO "Diagnostic Systems", Russia). RESULTS: IgG antibodies to HEV were detected in 87 (5.9%) of 1472 examined pregnant women, IgM antibodies -in 64 (4.8%) of 1378, while 5 (0.34%) samples were simultaneously positive for IgG and IgM antibodies. The rates of detection of antibodies to HEV in women of three age categories from 17 to 36 years old in the studied and control groups were similar. The analysis of the seasonal dynamics of HEV seroprevalence in pregnant women in the period from February to September 2019 showed a tendency towards an increase in the values of the positivity coefficient of specific IgM antibodies by the beginning of the autumn. Antibodies to HEV were detected with highest frequency in women from Osh region. CONCLUSIONS: A high risk of HEV infection for pregnant women in the surveyed region had been shown.

[The estimation of the hepatitis E proportion in the etiological structure of acute viral hepatitis in certain regions of of Kyrgyzstan.]

Despite the fact that the Kyrgyz Republic (KR) belongs to the highly endemic regions of the world for hepatitis E, the true extent of the spread of this infection in the country remains poorly understood. It was estimated the prevalence of serological markers of hepatitis E virus (HEV) infection among patients with acute viral hepatitis (AVH) from the regions of the Kyrgyz Republic with a high level of seroprevalence previously established by us. Blood sera samples of hepatitis patients who were admitted to hospitals of Kyrgyzstan in the period 2018-2019 were examined by the enzyme immunoassay method using the kits «DS-ELISA-Anti-HEVIgG¼ and «DS-ELISA-ANTI-HEV-IgM¼ (RPC Diagnostic Systems, Russia). IgG and IgM antibodies to HEV were detected in 103 of 344 studied samples (29.9%). Most often, seropositive specimens were detected among people of age groups under 20 and over 40 years old. Hepatitis with the fecal-oral mode of transmission was dominated in the structure of AVH: the specific gravity of hepatitis E was 47.9%, hepatitis A - 35.32%. Markers of mixed infections with other hepatitis viruses have been detected in 40.4% IgM-positive individuals. Thus, high prevalence of serological markers of HEV infection in the territory of Kyrgyzstan during the interepidemic period had been shown. The necessity of including the determination of serological markers of hepatitis E into the algorithm for the comprehensive diagnosis of AVH in patients of all age groups with liver pathology had been confirmed.

[The analysis of sero-prevalence of virus of hepatitis E among patients with HIV-infection and syphilis.]

The infection with hepatitis E virus is one of causes of liver diseases in patients with secondary immunodeficiency, including HIVinfected ones. The study was carried out concerning analysis of rate of detection of serological markers of infection with hepatitis E virus in samples of blood serums of HIV-infected patients and other group of patients with expressed immuno-suppression - patients with syphilis. The sero-prevalence of hepatitis E virus on IgM-antibodies among HIV-infected patients in Moscow made up to 21.7% and 2.9% correspondingly. In the examined group from the Far-East region the highest sero-prevalence of hepatitis E virus on specific IgE-antibodies (73%) is established in the group of patients infected with HIV subtype B. The most frequently IgG and IgM antibodies to hepatitis E virus were detected in HIV-infected patients at the stage of disease 4B. The examined group of patients with syphilis the sero-prevalence of hepatitis E virus made up to 14.7% that significantly surpasses the given indicator in the group of healthy persons (1.7%). The increasing of the level of sero-postivity is demonstrated in the groups of patients with latent syphilis and on the second stage of disease. Therefore, the highest values of sero-prevalence of hepatitis E virus is observed in the groups of HIV-infected patients and patients with syphilis at late stages of disease. In the Russian Federation, the identification of antibodies to hepatitis E virus in HIV-infected patients depends of the region of residence.

[Development of an immunochromatographic test system for the detection of human enidermal growth factor].

A method was developed for the rapid detection of human epidermal growth factor based on a sandwich-format immunochromatographic assay. The contact between the sample and the test strip with immobilized immunoreagents initiates the fluid flow movement across the membrane components of the test strip, immunochemical reactions, and the formation of colored lines. Requirements on the configuration of the test system in order to achieve the lowest limit of detection were defined in the course of the development of the assay. It was shown that this method enables the detection of human epidermal growth factor within 5 min at concentrations as low as 10 pg/mL in aqueous solutions, urine, and the blood serum and plasma. The developed test system can be used for point-of-care diagnostics.

[Highly effective test-system for determination of the total antioxidant activity of human blood serum].

A highly effective test-system for quantitative characterization of the total antioxidant activity (TAA) of human blood serum (HBS), including methemalbumin (MetHa) as biocatalyst, H2O2 as the oxidant, o-phenylenediamine (PDA) as the acceptor of radicals and 2,2,5,7,8-pentamethylchroman-6-ol (PMC) as the inhibitor-calibrator, has been developed and proved under the laboratory environments. The test-system has been optimized for the concentrations of all the components, the reaction conditions and the PDA consumption monitoring at 37 degrees C in the medium of buffered physiological solution, pH 7.4 containing 5% DMFA and 0.5% DMSO. Under strongly standardized conditions by a comparison of the inhibiting action of the HBS and the calibrator PMC at 37 degrees C, the quantitative parameters of the HBS TAA were determined in microg of PMC, equivalent to 1 mg of HBS, or as a reverse value in mg of HBS, equivalent to the action of 1 microg of PMC. The values of the HBS TAA significantly varied for the group of healthy individuals and essentially decreased for the group of patients with thyroid gland pathologies. This underlies necessity of antioxidant therapy in these patients.